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The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Temporal relationship between subclinical atrial fibrillation and embolic events
Michela Brambatti1, Stuart J Connolly1, Michael R Gold1
1From the Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada (M.B., S.J.C., C.A.M., J.N., M.H., W.Q.D., J.S.H.); Clinica di Cardiologia, Università Politecnica delle Marche, Ancona, Italy (M.B., A.C.); Medical University of South Carolina, Charleston (M.R.G.); Cardiology Department, Loreto Mare, Napoli, Italy (C.M.); Queen Mary Hospital, Department of Medicine, University of Hong Kong, Hong Kong, China (C.P.L.); University of Groningen, University Medical Center Groningen, Groningen, Netherlands (I.C.V.G.); J.W. Goethe University, Frankfurt, Germany (S.H.H.); St Jude Medical, Sylmar, CA, and Zaventem, Belgium (M.C.); Clinique du Sud Luxembourg, Arlon, Belgium (G.H.M.); and Evangelical Hospital Bielefeld, Department of Medicine, Division of Cardiology, Bielefeld, Germany (C.W.I.).
Background:
Among patients with implantable pacemakers and defibrillators, subclinical atrial fibrillation (SCAF) is associated with an increased risk of stroke; however, there is limited understanding of their temporal relationship.
Methods And Results:
The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT) enrolled 2580 pacemaker and defibrillator patients aged ≥65 years with a history of hypertension but without a history of atrial fibrillation. Pacemakers and implantable cardioverter-defibrillators precisely logged the time and duration of all episodes of SCAF and recorded electrograms that were adjudicated by experts. We examined the temporal relationship between SCAF >6 minutes in duration and stroke or systemic embolism. Of 51 patients who experienced stroke or systemic embolism during follow-up, 26 (51%) had SCAF. In 18 patients (35%), SCAF was detected before stroke or systemic embolism. However, only 4 patients (8%) had SCAF detected within 30 days before stroke or systemic embolism, and only 1 of these 4 patients was experiencing SCAF at the time of the stroke. In the 14 patients with SCAF detected >30 days before stroke or systemic embolism, the most recent episode occurred at a median interval of 339 days (25th to 75th percentile, 211-619) earlier. Eight patients (16%) had SCAF detected only after their stroke, despite continuous monitoring for a median duration of 228 days (25th to 75th percentile, 202-719) before their event.
Conclusions:
Although SCAF is associated with an increased risk of stroke and embolism, very few patients had SCAF in the month before their event.
Clinical Trial Registration Url:
http://www.clinicaltrials.gov. Unique identifier: NCT00256152.
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